Pfizer bid for sickle cell drug developer GBT said to be imminent

Pfizer is on the brink of announcing a deal to buy Global Blood Therapeutics (GBT) and its oral therapy Oxbryta for sickle cell disease for around $5 billion, according to press reports.

A deal could be announced as early as today, when GBT is scheduled to report its second quarter results, according to a Wall Street Journal report citing people familiar with the matter. Neither GBT nor Pfizer has commented on the rumour.

If confirmed, it will be another example of Pfizer leveraging the windfall cash generated by its COVID-19 vaccine Comirnaty and oral antiviral therapy Paxlovid to beef up its pipeline of new therapies, coming a few months after it closed a $6.7 billion acquisition of Arena Pharma and made an $11.6 billion takeover bid for Biohaven.

GBT won FDA approval for Oxbryta (voxelotor) as a daily tablet for the treatment of SCD in patients aged 12 and over in 2019, extending its use to include younger children aged four and over last December, and earlier this year also got a green light from regulators in Europe for the over 12s.

The $125,000-a-year drug is a haemoglobin polymerisation inhibitor designed to prevent the deformation or 'sickling' of red blood cells associated with the disease. It has been tipped to become a $1 billion-plus product.

Sales of Oxbryta have been a little slow to gather momentum, mainly because of payer resistance in the US, but are picking up the pace with a 41% rise to $55 million in the first quarter of this year.

There are around 100,000 people in the US living with SCD, and more than 20 million globally, according to the FDA.

If a deal is forthcoming, Pfizer would also claim inclacumab, a P-selectin inhibitor in phase 3 testing for prevention of the painful vaso-occlusive crises that afflict people living with SCD, as well as an early-stage polymerisation inhibitor called GBT021601 intended as a follow-up to Oxbryta.

Other suitors are also reported to be circling GBT however, according to Bloomberg, whose report sparked a 33% spike in GBT shares to more than $68 on Friday, not far shy of the company's 52-week high of $73 and giving it a market capitalisation of more than $4 billion.